1. Field of Invention
The invention relates to a light shading structure, a filter substrate, an array substrate, and a display panel, and more particularly, to a light shading structure used to solve the problem of light leakage and having a function of liquid crystal flow guidance, and a color filter substrate, an active device array substrate, and an LCD panel having the light shading structure.
2. Description of Related Art
With the development of photoelectric techniques and semiconductor manufacturing techniques, the flat panel display with the advantages of being thin and light has gradually matured. Among flat panel displays, such as Liquid Crystal Displays (LCDs), Organic Electro-Luminescence Displays (OELDs), and Plasma Display Panels (PDPs), the LCD with advantages of high definition, high space utilization efficiency, low power consumption, and non-radiation has gradually become the market mainstream.
Generally, an LCD is composed of an LCD panel and a backlight module, wherein the LCD panel includes an active device array substrate, a color filter substrate, and a liquid crystal layer sandwiched there-between. And full color effects can be achieved by the color filter substrate.
FIG. 1 is a schematic view of a conventional color filter substrate. Referring to FIG. 1, the color filter substrate 100 mainly includes a substrate 102, black matrixes 104a, 104b, a plurality of color filter units 106, and a common electrode 108. The substrate 102 can be divided into a display region 102a and a non-display region 102b surrounding the periphery of the display region 102a. The black matrixes 104a, 104b are disposed on the substrate 102, wherein the black matrix 104a defines a plurality of sub-pixel regions 110 in the display region 102a; the black matrix 104b covers the non-display region 102b adjacent to the edge of the display region 102a. The color filter units 106 are respectively formed by a plurality of photoresists with different colors (e.g., red photoresist, green photoresist, and blue photoresist, etc.) through exposure, development, and other processes, and are correspondingly disposed in the sub-pixel regions 110 defined by the black matrixes 104. Moreover, a common electrode 108 is disposed on the surface of the black matrixes 104a, 104b, and the color filter units 106.
Referring to FIG. 1 again, the main function of the black matrix 104a of the display region 102a is to separate emergent lights with different colors, so as to increase the color contrast and the color purity when displaying. Moreover, the black matrix 104b covering the non-display region 102b adjacent to the edge of the display region 102a is used to avoid light leakage through the non-display region 102b. 
In the early days, black matrixes 104a, 104b were usually made of Chromium (Cr), such that the black matrixes 104a, 104b made of Cr have preferred light shading effects. However, since Cr causes environmental pollution, it has gradually been forbidden for use. Considering environmental protection, using green materials has currently become the main trend. Therefore, in the current processes, resin is used to replace Cr in most cases.
However, using resin will cause another problem. Since the light shading effect of resin is weaker than that of Cr, part of the light will still penetrate through the black matrix 104b of the non-display region 102b and leak to the outside, so as to result in light leakage at the non-display region 102b adjacent to the display region 102a. Particularly with the development of LCD panels of high brightness and large size, the above light leakage phenomenon will be more severe in LCD devices with a high-brightness backlight module.
Further, when the above color filter substrate 100 is used for manufacturing an LCD panel (not shown), the liquid crystal (not shown) is disposed on the color filter substrate 100, and then, a sealant (not shown) is used to adhere the color filter substrate 100 and the active device array substrate (not shown) together. The liquid crystal may flow to the location of the sealant, and if the liquid crystal is in contact with the un-solidified sealant, it will be contaminated and the quality of the LCD panel will be deteriorated.